Hello, first off this is definitely a finicky situation, especially considering the on going event. While it is true you did not engage the police directly you did put yourself in a position to potentially get involved with a fire fight with the cops. While that may not have happened I am sure you can see how it could be viewed like that and seemed like you had little regard for you life in that moment. Do keep in mind though even if you don't begin shooting even aiming your weapon at an officer can be taking as initiating a violent encounter.
Though all things considered as you quoted in the rules regarding police PKs you must be the one to initiate the violent altercation, which did not happen in this instance you were simply just trying to kill the perpetrator who had killed your friend. This is definitely a rough situation so I urge you to think a little differently next time, even if you had aimed your weapon at them directly, even accidentally, this would likely be a denial.